Method and device for demetallizing residual oil

Abstract

The present invention relates to the technical field of residual oil pretreatment, and in particular to a method and device for demetallizing residual oil. The method comprises the following steps: (1) in the presence of a catalyst, thermally converting residual oil and hydrogen to obtain a thermal conversion reaction product; (2) using the thermal conversion reaction product or the heavy component in the thermal conversion reaction product as a mixed raw material, mixing it with a solvent, and filtering the obtained mixture to obtain a metal-enriched residue and a filtrate containing demetallized residual oil; (3) recovering the solvent of the filtrate of the demetallized residual oil to obtain a recovered liquid and demetallized residual oil. The method can achieve the removal of metals from residual oil and has a high metal removal rate; in addition, the method has the advantages of strong raw material adaptability, continuous operation, simple process flow, etc., and is convenient for industrial production.

Description

Technical Field

[0001] The invention relates to the technical field of residual oil pretreatment, and in particular to a method and device for demetallizing residual oil. Background Art

[0002] Heavy metals (nickel, vanadium, iron, calcium, etc.) in heavy oil are the main cause of catalyst deactivation in catalytic processing. Therefore, in order to ensure the operating time or catalyst consumption of the catalyst, the fixed-bed residue oil hydrogenation process generally requires the metal content in the feed to be no more than 120μg / g. In order to extend the operating cycle of the device, some companies even control the metal content of the raw materials to below 60μg / g; heavy oil catalytic cracking generally requires the metal content in the feed to be no more than 20μg / g. In recent years, the degree of heaviness and inferiority of crude oil has intensified, and the metal content in it has also shown an increasing trend year by year. Therefore, efficient demetallization of crude oil or heavy oil to meet the requirements of subsequent processing technology has become an inevitable trend and research hotspot.

[0003] CN110194966A discloses a method for demetallizing residual oil, which adopts solvent dilution and electrostatic agglomeration combined technology to realize demetallization of residual oil. The specific operation is to mix residual oil with fresh solvent at a certain temperature, reduce the viscosity of residual oil, make metal-containing components (such as colloid and asphaltene) in residual oil collide with each other, and then make metal-containing components agglomerate into sediment with higher density under the agglomeration effect of electric field, so as to realize demetallization treatment of residual oil. The method mainly makes metal-containing components agglomerate into sediment with higher density under the action of electric field, which is mainly a physical separation process. It is mainly used for electric desalting and dehydration in refineries, and is less used in demetallization. Moreover, this process produces about 30% heavy residual oil with high metal content, which is difficult to be processed later.

[0004] CN103374415A discloses a method for removing nickel and vanadium from hydrocarbon oil. The method comprises contacting a demetallization composition with a hydrocarbon oil mixture under microwave reaction conditions, and then performing oil-water separation on the contact product under electro-desalting conditions to obtain a hydrocarbon oil product from which nickel and vanadium have been removed. The demetallization composition comprises a demetallization agent, a hydrogen supply agent, a chelate, a phase transfer agent and a solvent, and the demetallization agent is a substance capable of reacting with nickel and vanadium in hydrocarbon oil, such as dimethyl phosphite or trimethyl phosphite. The method can achieve a metal nickel removal rate of >75% and a vanadium removal rate of >85%. However, the method has a narrow adaptability to raw materials and is not suitable for industrial implementation.

[0005] Therefore, a new method for demetallization of residual oil is urgently needed. Summary of the invention

[0006] The purpose of the present invention is to overcome the problems of severe reaction conditions, complex process flow, low metal removal rate, narrow raw material adaptability, etc. in the existing residual oil demetallization method, and to provide a new residual oil demetallization method and device, which can effectively improve the metal removal rate in the residual oil and has strong raw material adaptability.

[0007] In order to achieve the above object, the first aspect of the present invention provides a method for demetallizing residual oil, which comprises the following steps:

[0008] (1) in the presence of a catalyst, subjecting residual oil and hydrogen to a thermal conversion reaction to obtain a thermal conversion reaction product;

[0009] (2) using the thermal conversion reaction product or the heavy component in the thermal conversion reaction product as a mixed raw material, mixing it with a solvent, and filtering the obtained mixture to obtain a metal-enriched residue and a filtrate containing demetallized residual oil;

[0010] (3) The filtrate of the demetallized residual oil is subjected to solvent recovery to obtain a recovered liquid and the demetallized residual oil.

[0011] The second aspect of the present invention provides a residual oil demetallization device, the device comprising: a thermal conversion reaction unit, a mixing unit, a filtering unit, and a solvent recovery unit connected in sequence;

[0012] The thermal conversion reaction unit is used to perform a thermal conversion reaction on residual oil and hydrogen in the presence of a catalyst to obtain a thermal conversion reaction product;

[0013] The mixing unit is used to mix the thermal conversion reaction product or the heavy component in the thermal conversion reaction product as a mixed raw material with a solvent to obtain a mixture;

[0014] The filtering unit is used to filter the mixture to obtain metal-enriched residue and filtrate containing demetallized residual oil;

[0015] The solvent recovery unit is used to recover the solvent from the filtrate containing the demetallized residual oil to obtain a recovered liquid and the demetallized residual oil.

[0016] Through the above technical scheme, the method provided by the present invention adopts the technical means of thermal conversion reaction, solvent dilution, filtration and solvent recovery, which can achieve the removal of metals in residual oil and has a high metal removal rate; in addition, the method has the advantages of strong raw material adaptability, continuous operation, simple process flow, etc., and is convenient for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The present invention is a schematic diagram of a residual oil demetallization device.

[0018] Description of Reference Numerals

[0019] I. Conversion reaction unit II, mixing unit III, filtration unit

[0020] IV. Solvent recovery unit 1, residual oil 2, catalyst

[0021] 3. Hydrogen 4. Mixed raw materials 5. Solvent

[0022] 6. Mixture 7. Metal-enriched residue 8. Filtrate containing demetallized residual oil

[0023] 9. Demetallized residual oil 10. Recovered liquid DETAILED DESCRIPTION

[0024] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0025] The first aspect of the present invention provides a method for demetallizing residual oil, the method comprising the following steps:

[0026] (1) in the presence of a catalyst, subjecting residual oil and hydrogen to a thermal conversion reaction to obtain a thermal conversion reaction product;

[0027] (2) using the thermal conversion reaction product or the heavy component in the thermal conversion reaction product as a mixed raw material, mixing it with a solvent, and filtering the obtained mixture to obtain a metal-enriched residue and a filtrate containing demetallized residual oil;

[0028] (3) The filtrate of the demetallized residual oil is subjected to solvent recovery to obtain a recovered liquid and the demetallized residual oil.

[0029] In some embodiments of the present invention, preferably, the physical property parameters of the residual oil meet the following requirements: density ≥ 1 g / cm 3 ; Asphaltene content ≥ 10wt%; Metal content ≥ 100μg / g; Further preferably, the physical properties of the residual oil meet the following requirements: Density 1-1.15g / cm 3 ; Asphaltene content is 10-20wt%; Metal content is 100-500μg / g. Wherein, the metal content refers to the sum of Ni and V content.

[0030] In the present invention, unless otherwise specified, density parameters are measured using the GB 13377 method; asphaltene content parameters are measured using the alumina adsorption method for determining four components of heavy oil; and metal content parameters are measured using the residual metal content (ICP method) method.

[0031] In the present invention, the type of the residual oil has a wide selection range, as long as the physical property parameters of the residual oil meet the above-mentioned limitations. Preferably, the residual oil is selected from at least one of atmospheric residual oil, vacuum residual oil, catalytic cracking slurry, coal tar, heavy oil and oil sands asphalt.

[0032] In the present invention, unless otherwise specified, the metals (e.g., Ni and V) in the residual oil exist in the form of porphyrin compounds, mainly in asphaltene, and are prone to coking under high temperature conditions. Therefore, the residual oil is subjected to hydrogen under mild reaction conditions and in the presence of a liquid bulk catalyst having high dispersibility, oil solubility and high affinity with asphaltene, while removing the metal, the lightweighting of asphaltene is enhanced, which has the advantages of high demetallization efficiency and high demetallization oil yield.

[0033] In some embodiments of the present invention, preferably, the catalyst is selected from an oily catalyst and / or a liquid phase catalyst.

[0034] In some embodiments of the present invention, preferably, the catalyst is selected from compounds containing at least one element selected from Group VB metal elements, Group VIB metal elements and Group VIII metal elements, preferably selected from organic compounds containing at least one element selected from Group VB metal elements, Group VIB metal elements and Group VIII metal elements, more preferably selected from at least one of molybdenum-containing organic compounds, tungsten-containing organic compounds, nickel-containing organic compounds, cobalt-containing organic compounds, iron-containing organic compounds, vanadium-containing organic compounds and chromium-containing organic compounds; further preferably, the catalyst is selected from at least one of carbonyl molybdenum, carbonyl iron, molybdenum cyclopentaneate, iron cyclopentaneate, ethyl-molybdenum hexanoate, ethyl-nickel hexanoate and dialkyl dithiocarbamate molybdenum.

[0035] In the present invention, the thermal conversion reaction is intended to remove the metals in the residual oil from the porphyrin compounds. Preferably, in step (1), the conditions of the thermal conversion reaction include: a temperature of 350-450°C, preferably 380-420°C; a hydrogen partial pressure of 4-16MPa, preferably 6-10MPa; a volume space velocity of 0.1-2h -1 , preferably 0.2-0.5h -1 ; Catalyst concentration is 50-1000μg / g, preferably 200-800μg / g; hydrogen to oil ratio is 100-2000Nm 3 / m 3 , preferably 350-700Nm3 / m 3 The hydrogen-to-oil ratio is equivalent to 1m 3 For residual oil, the amount of hydrogen is 100-2000Nm 3 , preferably 350-700Nm 3 The use of optimal conditions is more conducive to the removal of metals from residual oil.

[0036] In some embodiments of the present invention, preferably, the boiling point of the heavy components in the thermal conversion reaction product is ≥350°C, preferably 350-480°C.

[0037] In the present invention, the thermal conversion reaction product is used as a mixed raw material, and direct solvent mixing and filtration can shorten the process, but the amount of solvent used and the mixing and filtration time are increased later; using the heavy component in the thermal conversion product as a mixed raw material must increase the process of fraction cutting, but the amount of solvent used and the mixing and filtration time can be reduced later.

[0038] In the present invention, the solvent is intended to dilute the demetallized residual oil in the thermal conversion product and reduce the residual oil viscosity. Preferably, the solvent is selected from polar solvents and / or non-polar solvents, preferably polar solvents; further preferably, the solvent is selected from aromatic compounds and / or petroleum fractions rich in aromatic compounds, preferably at least one selected from gasoline, toluene, catalytic diesel and aromatic extracted oil.

[0039] In some embodiments of the present invention, preferably, the weight ratio of the mixed raw material to the solvent is 1:0.01-8, for example, 1:0.01, 1:0.5, 1:1, 1:2, 1:3, 1:4, 1:5, 1:8, 1:10, and any value in the range of any two values, preferably 1:0.5-5. In the present invention, unless otherwise specified, in step (2), the amount of the solvent used is excessive relative to the mixed raw material.

[0040] In the present invention, since the viscosity of the thermal conversion reaction product or the heavy component in the thermal conversion reaction product is relatively high, in step (2), filtering operation cannot be performed without adding a solvent.

[0041] In some embodiments of the present invention, preferably, in step (2), the mixing conditions include: temperature of 20-350°C, preferably 50-250°C, more preferably 20-100°C; time of 0.1-2h, preferably 0.2-0.5h. The preferred conditions can make the thermal conversion product and the solvent mix more fully, which is conducive to the subsequent filtration to remove the metal-enriched residue and improve the yield of the demetallized residual oil.

[0042] In the present invention, there is a wide range of selection for the filtering method, as long as the metal-enriched residue and the filtrate containing demetallized residual oil in the mixture can be separated to obtain the metal-enriched residue and the filtrate containing demetallized residual oil, wherein the metal-enriched residue refers to the filter residue containing metal and catalyst.

[0043] In the present invention, the conditions for solvent recovery have a wide range of selection, as long as the recovered liquid and the demetallized residual oil in the filtrate of the demetallized residual oil are separated. Preferably, the conditions for solvent recovery include: a temperature of 50-350°C, preferably 80-200°C; a time of 0.2-2h, preferably 0.4-1h.

[0044] In the present invention, there is a wide range of options for the solvent recovery method. Preferably, the solvent recovery method includes but is not limited to flash evaporation, atmospheric distillation, reduced pressure distillation, etc.

[0045] According to the present invention, preferably, the method further comprises: returning the recovered liquid as a circulating solvent and mixing it into the solvent.

[0046] According to a particularly preferred embodiment of the present invention, the method comprises the following steps:

[0047] (1) in the presence of a catalyst, subjecting residual oil and hydrogen to a thermal conversion reaction to obtain a thermal conversion reaction product;

[0048] (2) using the thermal conversion reaction product or the heavy component in the thermal conversion reaction product as a mixed raw material, mixing it with a solvent, and filtering the obtained mixture to obtain a metal-enriched residue and a filtrate containing demetallized residual oil;

[0049] (3) recovering the solvent from the filtrate of the demetallized residual oil to obtain a recovered liquid and the demetallized residual oil;

[0050] The conditions of the thermal conversion reaction include: temperature of 380-420°C; hydrogen partial pressure of 6-10 MPa; volume space velocity of 0.2-0.5 h -1 ; Catalyst concentration is 50-1000μg / g, preferably 200-800μg / g; hydrogen to oil ratio is 100-2000Nm 3 / m 3 , preferably 350-700Nm 3 / m 3 ;

[0051] The mixing conditions include: temperature of 20-100° C. and time of 0.2-0.5 h.

[0052] The second aspect of the present invention provides a residual oil demetallization device, the device comprising: a thermal conversion reaction unit, a mixing unit, a filtering unit, and a solvent recovery unit connected in sequence;

[0053] The thermal conversion reaction unit is used to perform a thermal conversion reaction on residual oil and hydrogen in the presence of a catalyst to obtain a thermal conversion reaction product;

[0054] The mixing unit is used to mix the thermal conversion reaction product or the heavy component in the thermal conversion reaction product as a mixed raw material with a solvent to obtain a mixture;

[0055] The filtering unit is used to filter the mixture to obtain metal-enriched residue and filtrate containing demetallized residual oil;

[0056] The solvent recovery unit is used to recover the solvent from the filtrate containing the demetallized residual oil to obtain a recovered liquid and the demetallized residual oil.

[0057] According to the present invention, preferably, the recovery liquid outlet of the solvent recovery unit is connected to the solvent inlet of the mixing unit, so as to return the recovery liquid as a circulating solvent and mix it into the solvent.

[0058] A schematic diagram of a residual oil demetallization device provided by the present invention is as follows: Figure 1 As shown, the device comprises: a thermal conversion reaction unit I, a mixing unit II, a filtering unit III, and a solvent recovery unit IV connected in sequence;

[0059] The thermal conversion reaction unit I is used to perform a thermal conversion reaction on the residual oil 1 and hydrogen 3 in the presence of a catalyst 2 to obtain a thermal conversion reaction product; the mixing unit II is used to use the thermal conversion reaction product or the heavy component in the thermal conversion reaction product as a mixed raw material 4, and mix it with a solvent 5 to obtain a mixture 6; the filtering unit III is used to filter the mixture 6 to obtain a metal-enriched residue 7 and a filtrate 8 containing demetallized residual oil; the solvent recovery unit IV is used to recover the solvent from the filtrate 8 containing the demetallized residual oil to obtain a recovered liquid 10 and a demetallized residual oil 9;

[0060] The recovery liquid outlet of the solvent recovery unit IV is connected to the solvent inlet of the mixing unit II, so as to return the recovery liquid 10 as a circulating solvent and mix it into the solvent 5 .

[0061] The present invention will be described in detail below through examples.

[0062] Calculation formula:

[0063]

[0064]

[0065] Example 1

[0066] (1) In the presence of a catalyst (ethyl molybdenum hexanoate), a residual oil (specific components are listed in Table 1) and hydrogen are subjected to a thermal conversion reaction to obtain a thermal conversion reaction product; the conditions of the thermal conversion reaction include: a temperature of 420° C.; a hydrogen partial pressure of 10 MPa; a volume space velocity of 0.33 h -1 ; Catalyst concentration is 600μg / g; Hydrogen to oil ratio is 450Nm 3 / m 3 ;

[0067] (2) mixing the thermal conversion product as a mixed raw material with a solvent (toluene) at a weight ratio of 1:4 at 25° C. for 0.3 h, and filtering the obtained mixture to obtain a metal-enriched residue and a filtrate containing demetallized residual oil;

[0068] (3) The filtrate containing the demetallized residue oil was subjected to solvent recovery by distillation (temperature: 150°C, time: 0.5 h) to obtain a recovered liquid and demetallized residue oil S1, wherein the recovered liquid was returned as a circulating solvent and mixed into the solvent; the physical properties of the demetallized residue oil S1 are listed in Table 2.

[0069] Example 2

[0070] (1) In the presence of a catalyst (ethyl molybdenum hexanoate), a residual oil (specific components are listed in Table 1) and hydrogen are subjected to a thermal conversion reaction to obtain a thermal conversion reaction product; the conditions of the thermal conversion reaction include: a temperature of 420° C.; a hydrogen partial pressure of 10 MPa; a volume space velocity of 0.33 h -1 ; Catalyst concentration is 200μg / g; Hydrogen to oil ratio is 450Nm 3 / m 3 ;

[0071] (2) mixing the thermal conversion product as a mixed raw material with a solvent (toluene) at a weight ratio of 1:4 at 25° C. for 0.3 h, and filtering the obtained mixture to obtain a metal-enriched residue and a filtrate containing demetallized residual oil;

[0072] (3) The filtrate containing the demetallized residue oil was subjected to solvent recovery by distillation (temperature of 200°C, time of 0.5 h) to obtain a recovered liquid and demetallized residue oil S2, wherein the recovered liquid was returned as a circulating solvent and mixed into the solvent; the physical properties of the demetallized residue oil S2 are listed in Table 2.

[0073] Example 3

[0074] (1) In the presence of a catalyst (molybdenum cyclohexane acid), a residual oil (specific components are listed in Table 1) and hydrogen are subjected to a thermal conversion reaction to obtain a thermal conversion reaction product; the conditions of the thermal conversion reaction include: a temperature of 400° C.; a hydrogen partial pressure of 10 MPa; a volume space velocity of 0.5 h-1 ; Catalyst concentration is 400μg / g; Hydrogen to oil ratio is 400Nm 3 / m 3 ;

[0075] (2) mixing the thermal conversion product as a mixed raw material with a solvent (C9 aromatic hydrocarbon) at a weight ratio of 1:4 at 25° C. for 0.3 h, and filtering the obtained mixture to obtain a metal-enriched residue and a filtrate containing demetallized residual oil;

[0076] (3) The filtrate containing the demetallized residue oil was subjected to solvent recovery by distillation (temperature: 160°C, time: 0.6 h) to obtain a recovered liquid and demetallized residue oil S3, wherein the recovered liquid was returned as a circulating solvent and mixed into the solvent; the physical properties of the demetallized residue oil S3 are listed in Table 2.

[0077] Example 4

[0078] The method of Example 2 is followed, except that in step (2), the weight ratio of the thermal conversion product as the mixed raw material and the solvent (toluene) is replaced with 1:6, and the other conditions are the same to obtain the recovered liquid and the demetallized residue oil S4, wherein the physical properties of the demetallized residue oil S4 are listed in Table 2.

[0079] Example 5

[0080] The method of Example 1 is followed, except that in step (2), the solvent (toluene) is replaced by n-heptane, and the other conditions are the same, to obtain recovered liquid and demetallized residue oil S5, wherein the physical properties of the demetallized residue oil S5 are listed in Table 2.

[0081] Comparative Example 1

[0082] The method of Example 1 is followed, except that in step (1), no catalyst is added. Other conditions are the same, to obtain recovered liquid and demetallized residue oil DS1. The physical properties of the demetallized residue oil DS1 are listed in Table 2.

[0083] Table 1

[0084]

[0085]

[0086] Table 2

[0087]

[0088] Table 2

[0089]

[0090] It can be seen from the data in Table 2 that the method provided by the present invention can effectively remove metals from residual oil, especially under preferred conditions, the metal removal rate is as high as 96.5%, wherein the nickel and vanadium contents are reduced from 26 μg / g and 75 μg / g to 2.3 μg / g and 1.2 μg / g, respectively, and the demetallized residual oil can meet the feed demand for deep processing of residual oil.

[0091] Compared with Comparative Example 1, although a catalyst is added in Example 3, the reaction temperature is lower than that in Comparative Example 1. Temperature and catalyst concentration are both important factors affecting the demetallization rate. Although the metal removal rate in Comparative Example 1 is higher, the corresponding yield of enriched metal residue is also higher.

[0092] Compared with Example 2, the weight ratio of the mixed raw material and the solvent specified in Example 4 is not within the preferred protection range. The metal-enriched residue yield of Example 4 is slightly lower than that of Example 2, but the metal removal rate is slightly higher than that of Example 2.

[0093] Compared with Example 1, the solvent in Example 5 is n-heptane. Since toluene has stronger solubility than n-heptane, the yield of metal-enriched residue obtained by using n-heptane as solvent is much higher than that of the experiment using toluene as solvent. Correspondingly, the yield of demetallized residue oil is reduced. Since the metal concentration in the demetallized residue oil is 4 μg / g, which is slightly higher than the metal concentration in the demetallized residue oil obtained in Example 1, that is, the metal removal rate of Example 5 is slightly lower than that of Example 1.

[0094] Compared with Example 1, Comparative Example 1 did not add a catalyst during the thermal conversion reaction. Although Comparative Example 1 achieved a comparable demetallization effect, the yield of the enriched metal residue was significantly higher.

[0095] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for demetallizing residual oil, characterized in that: The method comprises the following steps: (1) subjecting residual oil and hydrogen to a thermal conversion reaction in the presence of a catalyst to obtain a thermal conversion reaction product; the catalyst is selected from at least one of a molybdenum-containing organic compound, a nickel-containing organic compound and an iron-containing organic compound; (2) the thermal conversion reaction product or the heavy component in the thermal conversion reaction product is used as a mixed raw material, mixed with a solvent, and the obtained mixture is filtered to obtain a metal-enriched residue and a filtrate containing demetallized residual oil; the boiling point of the heavy component in the thermal conversion reaction product is ≥350°C; the solvent is selected from aromatic compounds and / or petroleum fractions rich in aromatic compounds; (3) recovering the solvent from the filtrate containing the demetallized residue oil to obtain a recovered liquid and the demetallized residue oil; returning the recovered liquid and mixing it with the solvent; The conditions of the thermal conversion reaction include: temperature of 380-420°C; hydrogen partial pressure of 6-10 MPa; volume space velocity of 0.2-0.5 h -1 ; Catalyst concentration is 200-800μg / g; Hydrogen to oil ratio is 350-700 Nm 3 / m 3 ; The weight ratio of the mixed raw material to the solvent is 1:0.5-5; the mixing conditions include: temperature of 20-100°C; time of 0.2-0.5h.

2. The method according to claim 1, wherein: The physical properties of the residual oil meet the following requirements: density ≥ 1 g / cm 3 ; Asphaltene content ≥ 10wt%; Metal content ≥ 100 µg / g; And / or, the residual oil is selected from atmospheric residual oil and vacuum residual oil.

3. The method according to claim 2, wherein: The physical properties of the residual oil meet the following requirements: density is 1-1.15 g / cm 3 ; Asphaltene content is 10-20wt%; Metal content is 100-500 µg / g.

4. The method according to claim 1, wherein: The catalyst is selected from at least one of carbonyl molybdenum, carbonyl iron, molybdenum naphthenate, iron naphthenate, ethyl-molybdenum hexanoate, ethyl-nickel hexanoate and dialkyl dithiocarbamate molybdenum.

5. The method according to claim 1, wherein: The boiling point of the heavy components in the thermal conversion reaction product is 350-480°C; And / or, the solvent is selected from at least one of toluene, catalytic diesel and aromatic extracted oil.

6. The method according to claim 1, wherein: The solvent recovery conditions include: temperature of 50-350°C; time of 0.2-2h; And / or, the solvent recovery method is selected from at least one of flash evaporation, atmospheric distillation and reduced pressure distillation.

7. The method according to claim 6, wherein: The solvent recovery conditions include: temperature of 80-200° C.; time of 0.4-1 h.

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